Risk factors for older people utilizing care services in the long-term care insurance system

• Health deterioration to care level 1 or higher is a major public health concern. • Male sex is an independent risk factor for health deterioration requiring care level. • Dementia is an independent risk factor for health deterioration requiring care level. • Support level 2 is an independent risk factor for health deterioration requiring care level. • Social participation may protect against health deterioration to care level. Preventing the deterioration of health of older adults who need preventive care services from the “support level” to the “care level” in the long-term care insurance (LTCI) system in Japan is an important issue. This study aimed to explore the risk factors related to the deterioration of health among service users at the support level of LTCI. The participants were 200 Japanese community-dwelling older adults aged ≥ 65 years who were newly certificated as “support level” and used preventive care services. The users’ physical and cognitive conditions were assessed based on the primary doctor’s opinion and the Kihon checklist. The outcome event was defined as certification at care level 1 or higher. Cox models were used to assess the risk of health deterioration, with adjustments for age, sex, family composition, body mass index, frailty, stroke, dementia status, baseline support level, and social participation in community support projects in the LTCI system. The 5-year support level maintenance rate was 49.1%. Male gender (hazard ratio [HR] = 1.7), support level 2 (HR = 2.1), and dementia (HR = 2.1) were identified as factors associated with an adverse outcome, whereas social participation was identified as a preventive outcome (HR = 0.4). Male gender, support level 2, and dementia were associated with health deterioration among users from the support level to the care level in the LTCI system in Japan. On the other hand, social participation in community support projects may delay deterioration of health.